The present invention relates to a vaporizing device and, particularly but not exclusively, to a vaporizing device for vaporizing liquid medication.
One of the known nebulizers extensively used is ultrasonic nebulizer, which utilizes ultrasonic vibration waves to atomize or vaporize liquid. One disadvantage of ultrasonic nebulizers is that the mist produced is usually about 1-10 micron in size, which is not sufficiently fine for the respiratory tract of a patient to absorb medication. In addition, by reason of the complicate mechanism, large physical size and high power consumption, typical ultrasonic nebulizers are often only suitable for hospital and household use, and they are inconvenient to carry in transit or during travelling for use anytime and/or anywhere as needed.
The invention seeks to mitigate or at least alleviate such problems by providing a hand-held compressor nebulizer, which is lightweight, compact and convenient to carry and can be used at any moment, with a relatively smaller vaporized particle size.
According to the invention, there is provided a hand-held compressor nebulizer suitable for vaporizing liquid medication, comprising a casing, an air pump located within the casing an electric motor located within the casing for driving the air pump, and an electrical switch for controlling the operation of the motor. The nebulizer includes a liquid medication supply unit for supplying liquid medication and a vaporizing unit, both provided on the upper part of the casing. The vaporizing unit comprises an upper vaporizing chamber and a lower vaporizing chamber, the lower chamber including a reservoir into which the liquid medication supply unit is to supply liquid medication. The vaporizing unit includes a hollow conical member located within the lower vaporizing chamber and defining an internal conical passage having a relatively smaller upper end and a relatively larger lower end, the lower end being in communication with the air pump for receiving an upward airflow produced by the air pump. The airflow increases in speed in the upward direction and creates a negative pressure upon exit from the upper end of the conical passage. The vaporizing unit further includes a vaporizing jacket having a tapered interior and disposed around the conical member to form a narrow gap between the jacket and the conical member. The gap has an upper end in the vicinity of the upper end of the conical passage and a lower end in communication with the reservoir, such that the negative pressure can cause, by way of suction, liquid medication in the reservoir to move upwards along the gap and subsequently be vaporized by the airflow upon exit from the upper end of the gap.
Preferably, the upper vaporizing chamber is formed within the vaporizing unit and the lower vaporizing chamber is defined by a member extending across an uppermost end of the casing.
It is preferred that the liquid medication supply unit comprises a holder for holding a liquid medication box closed by a sealing tape, and a slider for piercing open said tape to allow liquid medication in said box to flow out into the reservoir.
It is further preferred that the medication box holder is located on the upper vaporizing chamber, and that the slider and said medication box are arranged on opposite sides within the holder, which slider is resiliently biased away from said medication box by means of a spring and is movable against the action of the spring to pierce through said tape.
Preferably, the vaporizing unit includes a lid having an air inlet above the upper vaporizing chamber to enable communication of the upper vaporizing chamber with the ambiant atmosphere, and an adjuster provided immediately below the lid for movement to adjust the opening size of the air inlet.
Preferably, the air pump is one of a valve-type pump and a plunger-type pump.
Preferably, the motor has a power rating of substantially 18 watt.
Preferably, the sealing tape is made of one of paper and tin foil.
Advantageously, the nebulizer may have a maximum size of 7 cmxc3x976 cmxc3x9723 cm, and a maximum weight of 750 grams.
In a preferred embodiment, the upper and lower ends of the conical passage defined by the conical member are substantially 0.7 mm and 3.0 mm in diameter respectively.
It is preferred that the gap formed between the jacket and the conical member is conical and has a gap width of substantially 0.5 mm.